JPH05101354A - Image recording and reproducing device - Google Patents

Abstract

PURPOSE:To optimally control the position of a movable rotary head and another rotary head without providing a head position detection circuit, in the image recording and reproducing device providing with the movable rotary head for special reproducing and a fixed rotary head for recording and capable of recording and simultaneously reproducing. CONSTITUTION:A detection circuit 8 detects the envelope output of the movable rotary head 2 when an image signal is recorded by the fixed rotary head 3, and magnitude of the output is measured by a detection circuit 9. Also, a control circuit 5 controls the drive of the movable rotary head 2 so that the detected envelope output is maximum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording / reproducing apparatus having a movable rotary video head for special reproduction.

[0002]

2. Description of the Related Art In a VTR, it has been practiced to drive a video head in a direction perpendicular to the head scanning direction by using a bimorph element or the like so that the head can correctly scan a recording track even during special reproduction. FIG. 3 is a block diagram showing the structure of a conventional VTR equipped with such a movable rotary video head for special reproduction. In the figure,
Reference numeral 1 denotes a cylinder having a pair of movable rotary heads 2 and 2 for special reproduction and fixed rotary heads 3 and 3 for recording, and 4
Is a movable rotary head position detection circuit for detecting the position of the movable rotary head 2, 5 is a movable rotary head control circuit for controlling the drive of the movable rotary head 2, 6 is a movable rotary head drive circuit for driving the movable rotary head 2, 7 Is a recording signal output circuit for outputting a recording signal to the fixed rotary head 3.

In the above-mentioned VTR, the movable rotary head 2 for special reproduction has its stop position always kept at the same position when the drive of the head 2 is stopped due to variations in the apparatus and the control circuit, aging and the like. Don't Therefore, the positional relationship between the fixed rotary head 3 for recording and other movable rotary heads is disturbed, and an appropriate reproduction signal cannot be obtained. Therefore, a movable rotary head position detection circuit 4 using a sensor or the like for correcting the position with another rotary head is provided,
The movable rotary head control circuit 5 corrects the position of the movable rotary head 2 via the drive circuit 6 according to the detected position.

[0004]

In the conventional image recording / reproducing apparatus, since the stop position of the movable rotary head is not constant during reproduction as described above, a sensor for correcting the position of the movable rotary head is used. There is a problem in that the structure becomes complicated because it is necessary to provide a movable rotary head position detection circuit using the above.

The present invention has been made in view of these problems, and it is possible to provide a movable rotary head, a fixed rotary head for recording, and other rotary heads without providing a head position detection circuit using a sensor or the like. It is an object of the present invention to obtain an image recording / reproducing apparatus capable of optimally controlling the positions of and.

[0006]

An image recording / reproducing apparatus of the present invention comprises a movable rotary head for normal reproduction and special reproduction,
An image recording / reproducing apparatus having a fixed rotary head for recording and capable of simultaneously reproducing a recorded image signal at the time of recording, in which the movable rotary head is positioned at a position where the simultaneous reproduction signal becomes maximum at the time of recording. Is.

[0007]

In the image recording / reproducing apparatus of the present invention, the position of the movable rotary head is controlled so that the simultaneous reproduction signal from the movable rotary head becomes maximum at the time of recording. Has an optimum positional relationship with the fixed rotary head for recording.

[0008]

1 is a block diagram showing the structure of an embodiment of the present invention, in which the same reference numerals as those in FIG. 3 indicate the same components. In the figure, 2 is a movable rotary head for normal reproduction and special reproduction, 3 is a fixed rotary head for recording, 5 is a movable rotary head control circuit for controlling the drive of the movable rotary head 2, and 6 is the movable rotary head 2. Movable rotary head drive circuit, 7
Is a recording signal output circuit that outputs a recording signal to the fixed rotary head 3, 8 is a movable rotary head envelope detection circuit that detects the envelope output of the movable rotary head 2, and 9 is the maximum value obtained by measuring the magnitude of the envelope output. A movable rotary head envelope maximum detection circuit for detecting the measurement result is input to the movable rotary head control circuit 5.

FIG. 2 shows a drum structure of the above-mentioned apparatus. A pair of movable rotary heads 2 and a fixed rotary head 3 for recording are attached to the outer periphery of a cylinder 1.

The image recording / reproducing apparatus having the above-described structure is capable of simultaneously reproducing the recorded image signal at the time of recording, and when performing the normal reproduction by the movable rotary head 2, the movable rotary head 2 is
It is arranged at a position where the simultaneous reproduction signal becomes maximum during recording.

That is, when the fixed rotary head 3 is recording an image signal, the envelope output of the movable rotary head 2 for reproduction is detected by the detection circuit 8, and the magnitude of the detected envelope output is detected by the detection circuit. It is measured at 9. This measurement result is input to the movable rotary head control circuit 5, and the control circuit 5 controls the drive of the movable rotary head 2 so that the detected envelope output becomes maximum. When the maximum envelope output is detected, the control of the movable rotary head 2 is stopped. As a result, the positions of the movable rotary head 2 and the video tape are optimized, and as a result, the positions of the movable rotary head 2 and the fixed rotary head 3 or other movable rotary heads are optimized.
In this case, a head position detection circuit using a sensor or the like is not required, so that the structure can be simple.

[0012]

As described above, according to the present invention, the position of the movable rotary head during normal reproduction is controlled to a position where the simultaneous reproduction signal becomes maximum during recording. Without providing a position detection circuit using a sensor,
The positional relationship with the fixed rotary head for recording or another movable rotary head is optimized.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a plan view showing a drum configuration of the apparatus shown in FIG.

FIG. 3 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 2 Movable rotary head 3 Fixed rotary head 5 Movable rotary head control circuit 8 Movable rotary head envelope detection circuit 9 Movable rotary head envelope maximum detection circuit

Claims (1)

[Claims] 1. An image recording / reproducing apparatus comprising a movable rotary head for normal reproduction and special reproduction, and a fixed rotary head for recording, capable of simultaneously reproducing recorded image signals at the time of recording. The image recording / reproducing apparatus is characterized in that it is positioned at a position where the simultaneous reproduction signal becomes maximum.